Seasonal changes can significantly impact mood, especially for individuals with mood disorders like major depressive disorder and bipolar disorder. Many people notice their symptoms worsen during darker, shorter days, but the precise reasons for this have long been unclear. While mood disorders are already the leading cause of disability worldwide, up to 30% of individuals with depression or bipolar disorder experience a distinct seasonal pattern in their symptoms.
Understanding the role of environmental factors like sunlight in these patterns could open the door to better treatment and self-management strategies. A recent study, published in PLOS Mental Health, sheds light on how sunlight exposure influences physical activity in people with depression. The study found that depressed individuals tended to be less physically active during the day, but this inactivity was closely linked to the amount of daylight and sunlight intensity.
More sunlight led to increased physical activity, suggesting that longer days and brighter light may help mitigate some depressive symptoms. Interestingly, the study also suggests that individuals with depression may have an altered physiological response to sunlight, making them less able to capitalise on its benefits. These findings could lead to the development of digital tools that track sunlight exposure and physical activity, offering clinicians a new way to monitor and manage seasonal mood disorders.
This approach could help people better .